Cholesteric liquid crystal inductive asymmetric polymerisation of thiophene monomers

Abstract

The thermotropic properties of cholesteric liquid crystal as a polymerisation medium for the synthesis of chiral polymers from achiral monomers were clarified. The chiral reaction medium was successfully employed to synthesise chiral polymers from thiophenes as achiral monomer. The polythiophenes thus prepared exhibit intense circular dichroism imparted by the physical chiral continuum of the reaction field. The chiral aggregate of the present polymers displays structural chirality, with optical activity derived not from the chirality of the individual main‐chain but from the chiral architecture. The chiral polymers do not exhibit a thermotropic cholesteric liquid crystal phase but nematic liquid crystal character due to the release of the chiral architecture upon heating.

Keywords:

• chiral conjugated polymers
• liquid crystal polymers
• matrix
• molecular imprinting

Acknowledgments

We would like to thank Hiroshi Ayukawa of the University of Tsukuba for assistance. Gratitude is extended to the Chemical Analysis Center of the University of Tsukuba for NMR spectra and elemental analysis data, and to the Engineering Workshop of the University of Tsukuba for glasswork. Prof. K. Akagi of Kyoto University is also gratefully acknowledged for CPL measurements.